Traditional methods of tissue repair to the shoulder or other joint areas are accomplished through open surgery. For example, rotator cuff repair is a type of surgery to fix a torn tendon in the shoulder. The rotator cuff is a group of muscles and tendons which form a covering, or a “cuff,” around the top of the upper arm bone, referred to as the humerus. The rotator cuff holds the humeral head in place in the shoulder joint and enables the arm to elevate and rotate.
The rotator cuff may tear through a single traumatic injury or overuse. A partial tear may require only a trimming or smoothing procedure referred to as a “debridement.” A complete tear, however, may be repaired by suturing the two sides of the tendon back together. Moreover, if the tendon is torn away from a location referred to as the greater tuberosity atop the humerus, it is reattached directly back to the humerus.
One method to attach the tendon back to the humerus is accomplished through open surgery. Open surgery requires the surgeon to make a two to three-inch incision in the shoulder area. The deltoid muscle is then cut through and/or separated in order to gain access to the damaged tendon. A small trough at the top of the humerus is created and small holes are drilled therethrough. Transosseous sutures are weaved or stitched through the rotator cuff and passed through the small holes to secure the rotator cuff to the humerus. Alternatively, anchors may be used to attach the tendon to the humerus. Although an effective method of repairing detached rotator cuff tendons, open surgery is not without its consequences. Pain, swelling, increased chance of infection, and prolonged recovery times are just a few examples of the adverse effects of open surgery.
To reduce the complications associated with open surgery, another method of repairing a torn rotator cuff is preformed arthroscopically. Arthroscopic surgery has some advantages as a result of its minimally invasive nature. Thus, the risks of infection, blood loss, and the like, are lower than compared to open surgery. However, because the incisions made during arthroscopic surgery are typically six to eight millimeters wide, the instruments used to repair the rotator cuff are more limited in size.
For example, suture anchors are commonly used in arthroscopic surgery to repair the rotator cuff tears. A suture anchor is configured to be secured into the humeral head and is designed to attach a portion of the damaged or torn rotator cuff to the greater tuberosity of the humeral head. The anchor portion is embedded into the bone and has at least one suture attached thereto. The suture extends from the anchor and secures the damaged rotator cuff tendon to the greater tuberosity of the humeral head.
However, in some patients, the bone quality in the greater tuberosity may be poor, thereby inhibiting, or providing less optimal, securement of the suture anchors within the humeral head. In such situations, the chances of bone fragmentation and anchor displacement may affect the integrity of the repair.
Attempts have also been made to use the techniques of open surgery repair, arthroscopically. For example, others have attempted to accomplish arthroscopic repair of the rotator cuff tendons through the bone tunnel and suture method explained above. However, the upper limits on the size of the available instruments which may be used to form bone tunnels are restricted by the diameters of the arthroscopic portals.